Overview
The SN3257-Q1 is an automotive-grade complementary metal-oxide semiconductor (CMOS) switch designed by Texas Instruments. This device is optimized for high-speed signal switching with low propagation delay, making it suitable for various automotive and industrial applications. The SN3257-Q1 features a 2:1 (SPDT) switch configuration with four channels, supporting multi-lane protocols such as SPI and I2S. It can handle bidirectional analog and digital signals and offers powered-off protection to prevent back-powering the supply rail through internal ESD diodes.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VDD Supply Voltage | 1.5 | 5.5 | V | |
| IDD Active Supply Current | 40 | 68 | μA | |
| IDD_STANDBY Supply Current when Disabled | 7.5 | 15 | μA | |
| RON On-Resistance | -900 | 0.01 | 900 | nA |
| VIH Input Logic High | 1.2 | 5.5 | V | |
| VIL Input Logic Low | 0 | 0.45 | V | |
| tTRAN Transition Time from Control Input | 160 | 350 | ns | |
| tON(EN) Device Turn On Time from Enable Pin | 12 | 35 | μs | |
| tOFF(EN) Device Turn Off Time from Enable Pin | 35 | μs | ||
| Propagation Delay | 95 | ps |
Key Features
- 2:1 (SPDT) switch configuration with four channels, ideal for multi-lane protocols like SPI and I2S.
- Supports high-speed signals with low propagation delay.
- Bidirectional analog and digital signal handling on source and drain pins.
- Powered-off protection up to 3.6 V to prevent back-powering the supply rail.
- Fail-safe logic circuitry to protect the device from potential damage when logic control voltages are applied before the supply voltage.
- 1.8 V logic compatible thresholds for both TTL and CMOS logic compatibility.
- Integrated pull-down resistor on logic pins to reduce system size and cost.
- Active low enable pin (EN) to control all channels simultaneously.
- Available in TSSOP (16-pin) and SOT-23-THIN (16-pin) packages.
Applications
- Automotive systems: Infotainment, navigation, and communication systems.
- Industrial control systems: Signal switching in industrial automation and control panels.
- Consumer electronics: Switching between different signal sources in multimedia devices.
- Medical devices: Signal routing in medical diagnostic and monitoring equipment.
- Telecommunications: Signal switching in communication equipment and networks.
Q & A
- What is the primary function of the SN3257-Q1?
The SN3257-Q1 is a CMOS switch designed to support high-speed signal switching with low propagation delay, particularly in 2:1 (SPDT) switch configurations.
- What types of signals can the SN3257-Q1 handle?
The device can handle bidirectional analog and digital signals on its source and drain pins.
- What is the significance of the powered-off protection feature?
The powered-off protection feature prevents back-powering the supply rail through internal ESD diodes when the supply voltage is removed.
- What logic compatibility does the SN3257-Q1 offer?
The device has 1.8 V logic compatible thresholds, ensuring compatibility with both TTL and CMOS logic.
- How does the integrated pull-down resistor benefit the system?
The integrated pull-down resistor on the logic pins reduces the need for external components, thereby reducing system size and cost.
- What is the role of the EN pin in the SN3257-Q1?
The active low enable pin (EN) controls all channels simultaneously; when low, it enables the switch based on the SEL pin state.
- In what packages is the SN3257-Q1 available?
The device is available in TSSOP (16-pin) and SOT-23-THIN (16-pin) packages.
- What are the typical operating conditions for the SN3257-Q1?
The device operates over a supply voltage range of 1.5 V to 5.5 V and a temperature range of –40°C to +125°C.
- What is the maximum propagation delay of the SN3257-Q1?
The maximum propagation delay is approximately 95 ps.
- How does the fail-safe logic circuitry protect the device?
The fail-safe logic circuitry allows voltages on the logic control pins to be applied before the supply voltage, protecting the device from potential damage.
